illustrates why many of the great trees of the temperate rainforest are vulnerable to
strong winds. The Douglas fir in the foreground once stood more than 80 feet tall. While
there are many shallow roots that fan out from the trunk base, there is no taproot that
might have held the tree upright. Since the teenager in the picture is almost six feet
tall, we may estimate that the roots extend from the trunk center about 15 feet. Yet, this
broad arrangement of shallow roots was apparently no substitute for a sturdy taproot,
without which the great fir was vulnerable to "blowdown." Wind is currently the
main source of natural disturbance in the shallow-rooted forests of the Northwest.
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